In this video, we see what happens when you drop powerful neodymium magnets through a short length of thick copper pipe, demonstrating Lenz's law. Long science story short: the magnets fall very slowly. The effect is really neat, and the video very simple (it's just one shot of a guy dropping magnets through a pipe...), but don't try this at home. Fooling around with strong magnets can hurt you. Fortunately, we have dudes on the Internet who'll do it for us:

(Via Devour.)